But in a field of one, how do you balance between chasing your best and quitting while you’re ahead?

Nearly 3,000 athletes from around the world have competed in the Winter Olympics. Hundreds arrived in Pyeongchang knowing that their odds of making the final for their event—let alone winning a medal—were vanishingly small. With a world or Olympic record out of reach, many of the competitors are left chasing an equally noble if more attainable goal: their personal best.

Besting your previous performance is a powerful motivator, whether at the Olympics or in life’s less-celebrated arenas. A personal record usually falls into the sweet spot of motivation that marks the ideal goal—neither so easy as to be uninspiring, nor so difficult as to be unattainable.

But in a field of one, how do you balance between chasing your best and quitting while you’re ahead? A new paper in the journal PNAS offers insight into how a personal best can both lure and repel people from competition.

Ashton Anderson from the University of Toronto and Etan Green of the Wharton School at the University of Pennsylvania analyzed a staggering dataset of 133 million online chess games that 70,000 people played between 2000 and 2015. (The sample includes some profoundly serious chess players who logged more than 178,000 games during that time, which averages out to about 30 games per day, every day, for 16 years.)

As players approached their own highest rating, they stepped up their games, exerting more effort to win. Yet as soon as they set a new personal ratings record, the likelihood that they would quit—which in this chess-mad group meant stepping away from the game for at least one hour—jumped by 20%.

On one hand, taking a break after achieving a sought-after goal seems a reasonable (and in the case of compulsive gamers, extremely healthy) thing to do. But in a different context, the desire to “go out on top” can be counterproductive. Technically speaking, this is the time you’re at your best. Would it make more sense to keep playing and see what else you can achieve, rather than walking away with the win?

The answer depends on what your goal is, and the only person who can decide that is you. That’s what makes the personal best such a helpful tool in reaching quantifiable goals. It’s personal, attainable, and you don’t need judges or a cheering crowd to go after it.